Lithiation and Delithiation Reactions of Binary Silicide Electrodes in an Ionic Liquid Electrolyte as Novel Anodes for Lithium‐Ion Batteries

Abstract

We investigated the lithiation and delithiation properties of pure binary silicide electrodes in an ionic liquid electrolyte as novel anodes for lithium‐ion batteries. Some electrodes maintain a high reversible capacity in the electrolyte, whereas they show a poor cycling performance in an organic electrolyte. The superior performance results from the high affinity for the transition metal that composes the silicide with Li. Based on reaction behavior analysis, the crystal structure of silicide is maintained during the cycling, and phase separation does not occur. The ionic liquid electrolyte suppresses the formation of cracks and exfoliation of the silicide layer from a substrate. In addition, a surface film formed on the silicide electrode through the reductive decomposition of the electrolyte has different components than that on a Si electrode, even in the same ionic liquid electrolyte. Soft X‐ray emission spectroscopy demonstrates that the pure silicide itself reacts with Li. The obtained results will provide significant insights into novel alloy‐based anode materials for lithium‐ion batteries.

Si and Ge‐Based Anode Materials for Li‐, Na‐, and K‐Ion Batteries: A Perspective from Structure to Electrochemical Mechanism

“…A Ni x Si y core Si 1− x Ge x shell NW has similar properties and 1100 mAh g −1 are obtained after 100 cycles . Other alloys include CuSi 2 or FeSi 2 which displayed volumetric capacities higher than that one of Si when cycled in the presence of an ionic liquid instead of the conventional organic electrolyte …”

“…It is crucial then to optimize the additive content and to use mixtures (VC+FEC) with synergetic effects that impact the electrode performance . Another alternative to stabilize the SEI layer, is the use of ionic liquids which allow a homogeneous lithiation with reduced strain, resulting in a structural integrity and improvement of the capacity retention …”

Computer Test of a New Silicene Anode for Lithium‐Ion Batteries

“…Recently, considerable efforts have been made in the search for materials for an efficient anode of lithium ion batteries of a new generation, [19][20][21][22][23][24] including optimized porous Si-based anode materials, [22] anode materials in a flexible version, [23] and the use of silicide electrodes using a liquid electrolyte. In the anode structure under consideration during charging the lithium ions fit into the gaps between the silicene sheets-a process known as intercalation.…”

“…LiPON, lithium phosphorus oxynitride, is an amorphous glassy material that can be used as an electrolyte material in thin film lithiumion batteries. Recently, considerable efforts have been made in the search for materials for an efficient anode of lithium ion batteries of a new generation, [19][20][21][22][23][24] including optimized porous Si-based anode materials, [22] anode materials in a flexible version, [23] and the use of silicide electrodes using a liquid electrolyte. [24] A distinctive feature of this work is the study of the functioning of a thin-film silicon anode at the atomic level.…”

Структурные изменения в пленках Si-CuSi при интеркаляции ионов лития

“…Для того чтобы повысить их циклический ресурс, предлагается использовать тонкие кремниевые пленки, в том числе наноструктурированные [1], легированные [2], упрочненные прослойками из более пластичных или более упругих материалов [3] и др. Активно исследуются композитные 3D-пленки, состоящие из аморфного кремния, армированного кристаллическими включениями силицидов переходных метал-лов [4,5]. Среди них выделяют композиты, содержащие силициды меди Cu x Si [6,7].…”